Red Phosphor and Luminous Element Using the Same
a technology of phosphor and phosphor, applied in the direction of luminescent compositions, luminescent screens, discharge tubes, etc., can solve the problems of low chemical stability against moisture, difficult to implement green and red color coordinates, and insufficient light emission intensity, so as to improve the color rendering of a white luminous element for a general lighting apparatus, the effect of improving color reproducibility and improving white uniformity
Active Publication Date: 2008-08-14
SEOUL SEMICONDUCTOR
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Benefits of technology
The present invention provides a novel red light phosphor with an alkaline earth metal-germanium metal-sulfur structure that can be used in a white luminous element for a general lighting apparatus. This phosphor has higher efficiency and stability against moisture than existing red light phosphors, and can be used in a white luminous element backlight that can substitute for a cold cathode fluorescent lamp (CCFL) in medium and large-sized TVs and has higher color reproduction and white uniformity. The technical effect of this invention is to improve the color rendering of a white luminous element for a general lighting apparatus.
Problems solved by technology
However, the (Sr,Ca)S:Eu red light phosphor has serious drawbacks in that its light emission intensity is not sufficiently high and its chemical stability against moisture is lowered.
Consequently, it is difficult to implement green and red color coordinates, which is regulated by the National Television Standard Committee (NTSC), after filtration through a color filter.
Therefore, there is a drawback in that they cannot be applied to a general lighting apparatus and a backlight for an LCD.
Method used
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Embodiment Construction
[0021]As described above, a (Sr,Ca)S:Eu red light emitting phosphor has been widely used as a red emission component that can emit white light by means of excitation of a blue luminous element. However, such a phosphor may easily react with moisture and thus its chemical structure may be changed to hydrogen disulfide and a sulfur oxide of alkaline earth metal. Consequently, the (Sr,Ca)S:Eu red light phosphor used together with a molding compound in a luminous element causes a chemical reaction that leads to gradual disappearance of a red light spectrum. Therefore, there is a phenomenon in which hydrogen disulfide produced as a by-product of the reaction corrodes a metallic component in the luminous element device, resulting in rapid deterioration of optical properties.
[0022]The reactivity of a compound can be explained on the basis of a theory for ionic field strength. The ionic field strength is expressed as follows:
Ionic Field Strength=m / b2
[0023]wherein ‘m’ is electrovalence, and...
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Abstract
The present invention relates to a phosphor and a luminous element using the same. The present invention provides a phosphor for absorbing a portion of light emitted from a light source and emitting light with a wavelength different from that of the absorbed light. The phosphor comprises a fluorescent material having an alkaline earth metal-germanium metal-sulfur structure that contains Ge and at least one element selected from the group consisting of Sr and Ca and is activated by Eu. The phosphor of the present invention increases a color rendering index (CRI) of a white luminous element for a general lighting apparatus, and a luminous element using the phosphor has an advantage in that it is suitable for a white luminous element backlight which can substitute for a cold cathode fluorescent lamp (CCFL) in medium and large-sized TVs and has higher color reproducibility and higher white uniformity.
Description
TECHNICAL FIELD [0001]The present invention relates to a phosphor and a luminous element using the same, and more particularly, a red light phosphor with a specific composition, which is suitable for implementing a white luminous element and has good efficiency, and a white luminous element using the same.BACKGROUND ART [0002]In general, a method of implementing a white luminous element is to combine a blue light emitting diode and a yellow light phosphor capable of being excited by blue light, or to combine green and red light phosphors capable of being excited by blue light. The former case has limitation on implementation of color rendering, whereas the latter case can implement a high color rendering index equal to or greater than 85.[0003]As for the structure of a white luminous element, it has a GaInN semiconductor structure, and comprises a combination of a blue light emitting diode having a maximum light emission wavelength of 430 to 470 nm and a phosphor capable of being ex...
Claims
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IPC IPC(8): H01L33/00C01F17/00H01L33/50
CPCC09K11/7731H01L33/502H01J1/63C09K11/7734H01L2224/48091H01L2924/181H01L2224/73265C09K11/77342H01L2924/00014H01L2924/00012
Inventor KIM, KYUNG NAMPARK, SANG MIMATSUOKA, TOMIZO
Owner SEOUL SEMICONDUCTOR